Had a post about this before, but was a LONG time ago so now closed. Much progress since then - the bike is actually finished and (roughly) ride-able. In fact, it is currently at a mechanics shop getting carb work done to resolve … well, the fact it has 37 year old carbs and was pulled apart and rebuilt, basically. It actually starts pretty nicely when cold, but after a minute or so either dies or revs up to idle at 5,000 rpm. I was able to limp it around the block in that condition, but it obviously needed work and while I can shape metal, even moving bits, I’m not a mechanic.
I have an imgur album with build / engineering info that might answer some common questions re design and safety - http://imgur.com/a/VR3WH